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ThesisItem Open Access Effect of processing and freezing procedures on the acrosome morphology of buck spermatozoa(Department of Animal Reproduction, College of Veterinary and Animal Sciences, Mannuthy, 1998) Ranjini, A; KAU; Prabhakaran Nair, KSix pooled semen samples (two ejaculates) of good quality from five Malabari crossbred bucks were processed and frozen in two different protocols to evaluate the effect of processing and freezing procedures on the acrosome morphology of buck spermatozoa. In protocol I, the samples were diluted 10 fold in Tris buffer before centrifuging twice and the final pellet was re-suspended in the non glycerolated fraction of Tris yolk diluent. The sample was glycerolated (six per cent), equilibrated (four hours), frozen (eight minutes), and thawed (250 C for 30 seconds). In protocol 11, centrifugation was done only once, after 15 fold dilution in Tris buffer. The re suspended pellet was glycerolated (seven per cent), equilibrated (three hours), frozen (10 minutes) and thawed (60° C for 10 seconds). The semen characters such as motility, live sperm, sperm abnormalities and acrosome abnormalities were evaluated at the end of washing and initial extension (stage I), cooling to 5° C (stage II), glycerolisation and equilibration (stage Ill) and freezing and thawing (stage IV). The results were compiled to evaluate the effect of different processing and freezing procedures on the semen characters in general and acrosome morphology in particular. The semen sample used for split sample dilution had a mean volume of 1.3282± 0.067 ml, creamy in colour, DDDD density, ++++ mass activity, pH of 7.275 2± 0.040 and a concentration of 2972 2± 293 millions per ml. No significant difference in the above semen characters were found between bucks. The initial sperm motility of 82.000 2± 0.606 was found to drop significantly during processing and freezing and the final post thaw motility obtained was 44.000 2± 0.790 in protocol I. Similarly in protocol II the initial motility dropped from 81.375 2± 1.089 to 44.750 2± 1.075 at the end of stage IV. Even though there was significant drop in motility between stages in both the protocols, there was no significant difference in the corresponding stages of the two protocols. It could be inferred that good post thaw motility was obtained in both the protocols. The fact that a single washing and centrifugation was only adopted in protocol II makes it a more acceptable procedure for buck semen freezing. The mean live sperm percentage of fresh semen was evaluated using both NE and NEG staining technique. The percentage of live sperms of 90.050 2± 0.801 was found to decrease to 54.250 2± 0.593 after freezing and thawing in protocol by NE staining. Similarly in protocol 11, the mean percentage of live sperms was found to reduce to 53.125 2± 0.793 with the same staining. Even though there was significant difference in the live sperm percentage between stages within protocol I and II no significant difference in the live sperm percentage between the corresponding stages of protocol I and I I . With NEG staining the initial live sperm percentage of 80.850 ± 1.494 was found to drop to 54.875 ± 0.677 in protocol I as against 53.400 ± 0.730 in protocol II. While there was significant difference in the live sperm percentage between stages within protocol I and II there was no variation between corresponding stages of the two protocols. A significantly lower percentage of live sperms was recorded with NEG staining when compared with NE staining probably on account of the fact that the differentiation of live and dead sperm was difficult in the former staining method as live sperms were stained light blue instead of colourless. The mean percentage of abnormal sperms of 3.050 ± 0.245 in fresh semen did not register any significant increase during processing. However, there was significant increase in the percentage of sperm abnormalities during freezing and thawing with the final abnormality percentage of 7.125± 0.706 in protocol I and 6.300± 0.36 in protocol II. The initial acrosomal abnormality of 8.825 in the fresh semen steadily rose to 23.375 in protocol I as against 19.825 in protocol II at the end of stage IV. There was no significant difference in the percentage of various acrosomal abnormalities between corresponding stages of the two protocols. However, there was significant increase in the acrosomal abnormalities during glycerolisation, equilibration, freezing and thawing under both the protocols. It was concluded that the processing and freezing under two different protocols did not significantly alter the post thaw motility, percentage abnormal and dead sperms and acrosomal abnormalities. A good post thaw motility and low acrosomal abnormality was obtained with a single washing of buck semen with 15 fold Tris buffer which was comparable with double washing with 10 fold Tris buffer.ThesisItem Open Access Management of Oestrous Cycle in Crossbred Cattle Using Prostaglandin(Department of Animal Reproduction, College of Veterinary and Animal Sciences,Mannuthy, 1994) Ajit Kumar, G; KAU; Madhavan, EWith the object of studying the efficacy of administration of prostaglandin F2 alpha in the management of oestrous cycle and fertility of fixed time insemination in induced oestrus, 96 heifers and cows which were cycling, selected from Kerala Agricultural University Livestock Farms, were allotted to three different groups. Sixteen heifers and 16 cows in group I were given 25 mg PGF2 alpha (Lutalyse) intramuscularly when they had functional corpora lutea, while in group II, 16 heifers and 16 cows were administered two injections of PGF2 alpha 25 mg each 13 days apart. Sixteen heifers and 16 cows were treated as control (Group III). Twelve heifers (75%) and 16 cows (100%) in group I and all animals in group II responded to treatment. Mean time taken for induction of oestrus was 56.64 and 65.44 h respectively in heifers and cows. This difference was statistically significant. Parity of cows significantly influenced the time taken for induction of oestrus. Duration of oestrus was significantly different between heifers (21.86 h) and cows (31.13h) of the experimental group. Significant difference in the duration of oestrus was observed among cows between experimental and control groups. All experimental animals which responded to PGF2 alpha showed marginal increase in physical characters of the reproductive tract like vulval oedema, hyperaemia of vaginal mucosa, vulval discharge and tonicity of uterine horns. Majority of the experimental animals showed medium to high intensity of oestrus compared to natural oestrus. The first insemination and overall conception rates of heifers in group I, inseminated 72 h post-treatment, were 33.33 and 66.67 per cent respectively as against 33.33 and 50 per cent when inseminated 96 h post-treatment. Cows in groupI recorded 25 and 62.50 per cent and 37.50 and 62. 50per cent first insemination and overall conception rates respectively when inseminated 72 h and 96 h post-treatment. When heifers and cows in group II were inseminated 72h after the administration of the second dose of PGF2 alpha, 12.50 and 25 per cent conceived at first insemination with overall conception rate of 62.50 and 37.50 per cent respectively. The corresponding values in group II, when inseminated 96 h, were 25 and 12.5 per cent and 50 and 12.5 per cent respectively. Among control 6.25 per cent of heifers and 18.75 per cent of cows conceived at first insemination. The first insemination conception rate of heifers of experimental (25%) and control groups (6.25%) were significantly different. However, overall conception rate did not differ between the three groups. There was no influence of parity or season on the conception rate. Similarly the time taken for induction of oestrus, duratioh of oestrus, physical changes of the reproductive tract during oestrus and intensity of oestrus did not affect the conception rate. Heifers and cows required 1.88 and 1.93 inseminations respectively per conception when treated with PGF2 alpha as against 3.14 and 3.33 in the control group. Though, the present investigation revealed that PGF2 alpha can be used in the management of oestrous cycle in crossbred heifers and cows with fixed time insemination, the high cost of the drug and the conception rate obtained warrant further studies on fertility in relation to detected oestrus and fixed time insemination after the administration of PGF2 alpha.ThesisItem Open Access Reproductive pattern and performance of nanny goats in Kerala(Department of Animal Reproduction, College of Veterinary and Animal Sciences, Mannuthy, 1992) Krishna Kumar, G; KAU; Sudarsanen, VA study to elucidate the reproductive pattern and performance of nanny goats under the agroclimatic conditions of Kerala conducted on a flock of 154 nanny goats of mixed genotype, Malabari, Saanen x Malabari and Alpine x Malabari, maintained under the All India Co – ordinated Research Project on goats for milk, Kerala Agricultural University, has revealed the following results and conclusions. The method adopted was detection of oestrus twice a day using a vasectomised buck and by clinical examination. On detection, all animals of good reproductive health were bred artificially with freshly collected semen extended in Tris buffered yolk extender and preserved at low temperature. A group of animals were given a second insemination after seven hours of the first insemination for a comparison of the success rate to single and double inseminations during a heat. Following breeding, the duration of gestation, durations of stages of parturition, presentation of kids, incidence of multiple birth and secondary sex ratio were also recorded. Daily record of maximum and minimum temperature for a period of one year of the study was maintained. The period was divided into four quarters almost in agreement with the four natural seasons and the conceptions during each of the quarters were related with their secondary sex ratio and birth weight records to know the influence of the environmental temperature on them. Placental area weight records were also maintained and by applying linear regression equation they have been correlated with the birth weight to establish that the birth weight difference was due to the influence of environmental temperature on placental growth and development. Goats were found to be polyoestrous and 61. 54 per cent came into oestrus during the period from April to September when the day is long. Of the two peak breeding activities noticed the greater one occurred in July and the other during November. Breeding activity was found to be low during the months of January and February. The duration of oestrous cycle was found to be 18 – 23 days but the cycle length varied from 6 to 140 days. 45.8 per cent of the animals had an oestrus duration of less than 18 days. Duration of oestrus varied from 12- 48 h. Cessation of oestrus was noticed in 84.8 per cent of animals by 36 h and in 93.26 per cent of animals by 48 h. Conception percentage to first time single and double inseminations during a heat were 33.93 and 42.85 respectively. Overall conception percentages for the above were 71.42 and 82.14 respectively. Average gestation length was 145.62 ± 0.23 days while with singleton, twin and triplet, the durations were 146.05 ± 144.86 ± 0.32 and 145.25 ± 1.03 days. In twin pregnancies and in pregnancies with male foetus/foetuses in both singleton and homogamous twin, was found to have lesser duration of gestation. Mean durations of the first, second and third stages of labour were 57.47 ± 10.29 , 14.52 ± 1.34 and 128.87 ± 4.84 min respectively. Presentation of kids at the time of birth was 88.9 per cent in anterior and the rest in posterior presentation. Secondary sex ratios of singleton and multiple pregnancies were 52.05 and 54.08 per cent with an overall of 53.22 per cent. No significant variation could be observed in the secondary sex ratio of kids those were conceived between seasons having variable environmental temperature. Mean birth weight of kids born during the three trimesters with mean environmental maximum temperature 39.0, 33.4 and 36.30 C were respectively 1.64, 1.92 and 1.88 kg. Between the trimesters having 39. 00 C and 33.40 C there was a significant increase in birth weight. A definite correlation was found to exist between the placental weight and birth weight and the placental area and birth weight. The following conclusions were derived : 1. There is a reproductive pattern difference as could be seen from the above as 61.54 per cent of the oestruses occurred during the period of long days, contrary to the belief that breeding season of goats is the short days. Peak breeding activity was also noticed during the month of July. An instinctive attempt to reduce the number of births during the months of heavy rain which is not conducive for the survival of the young could be appreciated from the low breeding activity seen during January and February. 2. The duration of oestrous cycle, oestrus, gestation and the first, second and third stages of parturition were found to be in consonance with the already available informations. 3. Two inseminations during a heat was found to improve the conception percentage over single insemination. 4. Incidence of multiple pregnancy was found to be lower in the flock. 5. Secondary sex ratio of the kids born was 53.22 per cent and it confirms well with the reports already available. Presentation of foetus was anterior in 88.9 per cent and the rest of posterior presentation. 6. Conception between periods of variable environmental temperature did not seem to influence the sex ratio, to significantly alter the secondary sex ratio. 7. Environmental temperature at the time of conception was found to significantly influence the birth weight of kids. From the correlation that could be established between placental weight and birth weight and between placental area and birth weight it could be inferred that the environmental temperature effect on birth weight is through its influence on placental development and growth.ThesisItem Open Access Superovulatory response, embryo collection and transfer in crossbred cows(Department of Animal Reproduction, College of Veterinary and Animal Sciences, Mannuthy, 1996) Unnikrishnan, M P; KAU; Suresan Nair, S POut of eleven crossbred cows superovulated with 2000 IU of PMSG on day eleven and 25 mg PGF2 alpha 48 h later, nine animals (81.8%) exhibited oestrum after an average interval of 39.44 ± 2.44 h. Average duration of oestrum was 40.00 ± 2.00 h with 66.7 per cent of them exhibiting intense heat signs and 33.3 per cent exhibiting only moderate heat signs. Average number of corpora lutea and unovulated follicles in both the ovaries put together was 6.67 ± 0.50 and 6.22 ± 0.57 respectively. Ovarian response was more in right ovary than in left ovary, though not statistically significant. Average fluid recovery on flushing was 79.5 per cent which was comparatively low. The average embryo recovery and percentage of embryo recovery were 3.38 ± 0.70 and 53.11 ± 10.18 respectively, which was comparatively lower. The reason for poor recovery of embryo was attributed to poor fluid recovery on flushing. The average number and percentage of transferrable embryo recovered were 1.50 ± 0.53 and 33.34 ± 10.14. Reason for these lower rates were attributed to loss of embryo quality, due to prolonged action of PMSG. Donors of parity over three performed better on superovulation and flushing, than those below three. Animals of age group six to nine years produced more transferrable embryos than cows of age group ten and above. A conception rate of 30 per cent was achieved after transfer of embryos to naturally synchronised recipients. Heifers appeared to be better recipients than cows. Although a high incidence of abortion was encountered, birth of an embryo transfer male calf was also recorded in the study. All the donor cows came into regular oestrous cycle within four months of superovulation treatment.ThesisItem Open Access Superovulation, Sychronisation of oestrus and embryo transfer in crossbred cows(Department of Animal Reproduction, College of Veterinary and Animal Sciences, Mannuthy, 1992) Suresan Nair, S P; KAU; Neelakanta Iyer, C PThe object of the present investigation was to ascertain the influence of varying doses of FSH and PGF2₻on various parameters of superovulation and embryo collections, with the ultimate aim of fixing the optimum dose of FSH and PGF2 ₻ required for successful superovulation in crossbred cows. Detailed investigation was made in a herd of 32 crossbred cows belonging to the University Livestock Farm, attached to the College of Veterinary and Animal Sciences, Mannuthy, during the period from April 1989 to December, 1991. The animals were randomly divided into 6 groups based on 3 doses of FSH and 2 doses of PGF2 ₻ administered. It was observed that 20 mg of FSH, with 25 mg of PGF2 induced satisfactory superovulation response and 20 mg of FSH with 15 mg of PGF2 ₻ resulted in better embryo quality. Further increase in the dose did not show any improvement in the responses. Right ovary showed more response than the left. Day 11 was found to be ideal for starting superovulation treatment, and day 6 for embryo collection, though statistically no significant influence was noticed by day of collection on superovulation response. Parity and age of donors had no influence on superovulation. Rainy and summer months were found to be better seasons for superovulation treatment than winter. Shorter duration (24 hr) of oestrum was noticed in more number of animals. 20 mg of FSH and 25 mg of PGF2 ₻ (group 3) yielded better cervical dilatation and flushing efficiency. Level of progesterone increased following superovulation treatment and declined 3 days before oestrum and reached the lowest level on day of oestrum. Pregnancy rate achieved was 33.3 per cent, but calving percentage was nil.ThesisItem Open Access Growth and reproductive performance of crossbred heifers in selected areas(Department of Animal Reproduction, College of Veterinary and Animal Sciences, Mannuthy, 1998) Rajeev, R; KAU; Aravinda Ghosh, K NGrowth and reproductive status of crossbred heifers under field condition were assessed and the role of calcium, phosphorus, copper, zinc and manganese with reproductive performance was evaluated with the aim of evolving suitable corrective measures in cases of those with impaired reproductive performance due to subnormal serum mineral status. One hundred and twelve heifers were subjected to repeated gynaecoclinical examination. It was observed that there were 36.6 per cent true anoestrum, 19.6 per cent under developed genitalia, 29.5 per cent normally cycling, 9.8 per cent repeat breeders, 3.6 per cent suboestrum and 0.9 per cent bilateral ovarian hypoplasia. From the above heifers 89 were randomly selected and classified based on the breeding history and repeated gynaecological examination as 15 normally cycling (control), 41 true anoestrous heifers, 22 under developedgenitalia and 11 repeat breeders. The daily weight gain obtained was 55.05 ± 4.2 g, 32.26 ± 2.49 g, 27.33 ± 3.4 g and 24.1 ± 4.8 g. The above result gave significant difference in weight gain between control animals and other groups. The growth rate of heifers might have influenced the normal reproductive performance. Serum samples drawn from 89 heifers were analysed for calcium, inorganic phosphorus and trace elements namely copper, zinc and manganese. Serum calcium and phosphorus were estimated by employing spectronic-20, i&hile trace elements were estimated through atomic absorption spectrophotometer. The serum calcium level obtained was 11.1 ± 0.31 mg%, 10.74 ± 0.13 mg%, 10.8 ± 0.2 mg% and 10.8 ± 0.42 mg% in normally cycling, true anoestrous, under developed genitalia and repeat * breeding heifers respectively. The serum levels of all the four groups were well within the normal range and no significant variation among the groups. Hence the influence of calcium on reproduction could not be established. The serum inorganic phosphorus was 4.87 ± 0.13 mg% in normally cycling heifers (control) as against 3.83 ± 0.09 mg% for true anoestrous heifers, 3.52 ± 0.1 mg% for underdeveloped genitalia and 4.7 ± 0.15 mg% for repeat breeders. The level was significantly lower (<0.05) in true anoestrous and underdeveloped genitalia compared to control group. It can be summarised that hypophosphataemia might be one of the cause for true anoestrum and under developed genitalia. Among the trace elements estimated the serum level of copper only was found to be significantly varying among normally cycling, true anoestrous and heifers with under developed genitalia. The serum copper in control group heifers registered a value of 1,26 ± 0.07 ppm which was significantly higher (P<0.01) than those recorded for true anoestrous heifers (O’. 9 ± 0.04 ppm) and heifers with under developed genitalia (0.71 ± 0.05), ajhile no statistical significant variation obtained between serum value of repeat breeders (1.27 ± 0.08 ppm) and the control group. It is therefore reasonable to assume that hypocupraemia as evidenced by lower serum value might have contributed to true anoestrum and under developed genitalia condition and not with that of repeat breeding condition. The serum zinc and manganese levels of control group were 1.71 ± 0.05 ppm and 0.04 ± 0.002 ppm respectively. The corresponding values for the true anoestrum heifers were 1.61 ± 0.03 ppm and 0.04 ± 0.002 ppm and for heifers with under developed genitalia group were 1.6 ± 0.05 ppm and 0.04 ± 0.002 ppm respectively. These values did not vary significantly from those of control group. The corresponding values for repeat breeders were recorded to be 1.73 ± 0.06 ppm and 0.04 ± 0.002 ppm which did not differ: significantly from the values obtained for control group. The result of supplementation with dicalcium phosphate and copper sulphate to the respective mineral deficient heifers with true anoestrum and under developed genitalia showed that the mineral supplementation could induce oestrum. The serum mineral status comparison at different level of feeding showed significant difference (P<0.05) in the serum phosphorus level as well as copper level of moderate plane group with that of low and poor plane groups. Hence the effect of plane of nutrition on serum mineral status could be established in case of serum phosphorus and copper. The soil level of calcium, phosphorus, copper, zinc and manganese found to be well within the normal range. The level of exchangeable calcium and available phosphorus were ranged 0.11-0.12 per cent and 0.05-0.06 per cent respectively. The available copper, zinc and manganese levels obtained were ranged 4.43-4.5 ppm, 5.3-5.44 ppm and 96.34-99.7 ppm respectively. The result showed that the soil mineral content did not influence: the serum mineral statusThesisItem Open Access Ovarian response to gonadotrophin releasing hormone in non-cyclic goats(Department of Animal Reproduction, College of Veterinary and Animal Sciences, Mannuthy, 1998) Aravinda Ghosh, K N; KAU; Mathai, EThe study was conducted to evaluate the effect of Gonadotropic Releasing Hormone (GnRH) on ovarian activity and its usefulness in restoring normal oestrous cycle in adult non-cyclic goats. A total of 60 healthy Malabari, Malabari x Saanen and Malabari x Alpine does aged one to four years, with a record of one or more kiddings and 45 days post partum belonging to Goat Farm of Kerala Agricultural University, Mannuthy were closely observed for a period of 60 days for the occurrence of oestrus and serum samples were collected at fortnightly intervals for the estimation of macro and micro minerals. Serum progesterone profile in eight cyclic and sixteen non-cyclic does, selected at random, were estimated by Radioimmunoassay using a coat-A-count progesterone kit. Out of eight non-cyclic does treated with potent GnRH anologue (Buserelin) three responded to single dose and one responded to a second dose. The oestrus was exhibited at a mean of 87.000 ± 9.950 h after the administration of GnRH analogue. The mean length of oestrous cycle and duration of oestrus in cyclic does were 20.313 ± 1.553 days and 37.500 ± 7.263 hrs while in GnRH responded does were 12.750 ± 0.830 days and 18.000 ± 4.240 hrs, respectively. The mean serum phosphorus level was found significantly higher in GnRH responded does (5.375 ± 0.205 mg per cent) as compared to cyclic does (4.800 ± 0.260 mg per cent) and non-cyclic does (4.770 ± 0.280 mg per cent). There was significantly higher serum copper level in GnRH responded (1.123 ± 0.089 ppm) and in cyclic does (1.160 ± 0.170 ppm) as compared to non-cyclic controls (0.830 ± 0.110 ppm) . The serum zinc level was significantly higher in non-cyclic (1.510 ± 0.430 ppm) as compared to cyclic (1.180 ± 0.120 ppm) and GnRH responded does (1.155 ± 0.091 ppm). There was no significant difference in the serum calcium, cobalt and manganese level between the three groups. The mean serum progesterone in cyclic does for the two consecutive cycles was 0.304 ± 0.087, 1.294 ± 0.382, 2.531 ± 0.758, 3.619 ± 0.794, 2.456 ± 0.430 and 0.871 ± 0.246 ng/ml and in GnRH responded does was 0.158 ± 0.026, 0.800 ± 0.177, 1.475 ± 0.334, 0.675 ± 0.236, 0.280 ± 0.030 and 0.120 ± 0.021 ng/ml on day one, four, six, ten, 14 and 18 of cycle, respectively. The overall mean serum progesterone during induced cycle in GnRH responded does was 0.535 ± 0.139 ng/ml which was significantly lower as compared to cyclic does (1.848 ± 0.339 ng/ml) but significantly higher as compared to untreated non-cyclic does (0.190 ± 0.106 ng/ml), Detailed biometry studies of pituitary ovary, uterus and cervix of GnRH responded does showed non-significant increase in the size and weight as compared to untreated non-cyclic does. The mean number and size of follicles were found significantly higher in GnRH responded as compared to non-cyclic does. The mean tissue ACP, ALP and LDH in the pituitary, ovary and uterus of GnRH responded does showed non significant increase as compared to untreated non-cyclic does. The mean LDH level in both ovaries together was significantly higher in GnRH responded does as compared to non-cyclic does. The present study confirms that GnRH administration in non-cyclic does has reactivated the ovary by increased follicular growth, maturation and corpus luteum formation. However, the length of induced oestrous cycle, duration and intensity of oestrus was significantly less in GnRH responded doesThesisItem Open Access Superovulation and embryo recovery in rabbits(Department of Animal Reproduction, College of Veterinary and Animal Sciences, Mannuthy, 1997) Sathesh Kumar, S; KAU; Suresh Nair, S PSuperovulation was induced in Newzealand White and Sovira. Chinchilla breeds of rabbits by administration of a single dose of 150 IU PMSG followed by double mating at induced cycle and 150 IU HCG soon after second mating to induce ovulation. The onset and intensity of oestrum, number of ovulations, embryo recovery and quality of embryos were studied and compared with those of the controls of the respective breeds. The mean interval from PMSG administration to onset of oestrus in both the breeds was 56.0 + 5.1 h. It was further observed that most of the treated animals showed intense oestrum when compared to controls. The ovulation rate based on the number of corporalutea in control animals of Newzealand White breed was 4.7 + 1.2 as against 22.0 ± 1.35 in the treated group. There was significant difference (P<0.01) in the ovulation rate between the groups. The percentages of embryo recovery, fertile embryos and transferrable embryos in the control group were 47.22, 86.7 and 92.3 while those of the treatment group were 31.67, 100 and 87.8 respectively. There was no statistically significant difference between the groups. While the control animals in Soviet Chinchilla breed has an ovulation rate of 6.7 ± 0.65, the treated rabbits showed a higher ovulation rate of 20.0 ± 3.2. There was significantly higher ovulation rate (P<0.01) in treated group when compared to controls. The embryo recovery rate, fertilized embryos and transferrable embryos in the control group were 53.33 per cent, 77.8 per cent and 93.8 per cent respectively. The corresponding values in the treatment group were 36.27 per cent, 69.82 per cent and 93.1 per cent respectively. There was no significant difference between the groups. No breed influence on the above parameters could also be noticed in this study It may be concluded that superovulation could be successfully induced in Newzealand White and Soviet Chinchilla breeds of rabbits with single dose of 150 IU PMSG, followed by 150 IU HCG soon after second mating. Eventhough there was superovulation, the embryo recovery rate was comparatively lower in the treated group probably on account of an altered oestrogen-progesterone profile interfering with the transport of the zygote, however the fertilization rate and the quality of the embryos were unaffected with the superovulation treatment.ThesisItem Open Access Effect of different glycerol concentrations on freezing of buck semen(Department of Animal Reproduction, College of Veterinary and animal Sciences, Mannuthy, 1995) Prasanth, V; KAU; Mathai, EWith the object of studying the effect of different concentrations of glycerol on post-thaw motility and fertility of frozen buck semen, five Malabari crossbred (Alpine x Malabari) bucks maintained at Artificial Insemination Centre and 75 does in heat, brought to the A. I. centre, College of Veterinary and Animal Sciences, Mannuthy, Thrissur were used. The average volume of semen was 0.71 ± 0.02 mI. Semen volume varied significantly between bucks. The average colour index was creamy, density was DDDD and the mass activity was ++++. The average pH of semen was 6.85 ± 0.01. The average sperm motility percentage was 85.83 ± 1.05. Motility percentage varied significantly between bucks. The average sperm concentration was 2842.33 ± 153.93 millions/mI. Highly significant difference in sperm concentration was noted between bucks. The average live sperm percentage was 91.03 ± 0.56. There was highly significant difference in live sperm percentage between bucks. Significantly higher percentage of sperm motility was noted in spermatozoa with seminal plasma than in spermatozoa without seminal plasma at 60 minutes of incubation. Slight increase in motility percentage was noted for spermatozoa with and without seminal plasma at 10 minutes of incubation. From 10 minutes to 60 minutes motility was gradually decreasing. Between bucks there was highly significant difference in sperm motility of incubated spermatozoa. Live sperm percentage was significantly higher for spermatozoa without seminal plasma at all time periods of cold shock. There was a rapid reduction in live sperm percentage at five minutes of cold shock. The live sperm percentages between bucks were significant at different time periods except at 10 minutes and 30 minutes of cold shock. The average time taken for reduction of methylene blue by spermatozoa with and without seminal plasma were 173.16 ± 8.77seconds and 197.00 ± 9.97 seconds respectively. Significant difference was noted in methylene blue reduction time between bucks. Average percentage sperm motility after washing was 76.71 ± 0.79. Maximum percentage motility after glycerolisation was obtained in six per cent glycerolated semen (67.85 ± 1.39). There was highly significant reduction in motility percentage after glycerolisation. Maximum post-thaw motility was obtained in six per cent glycerolated extender (42.00 ± 1.84). Highly significant reduction in motility percentage was noted after freezing. The conception percentage and kidding percentage were 47 .36 and 43. 85 respectively. Average gestation length was 149.85 ± 4.45 days. The number of kids per kidding averaged 1.7. Percentage of male and female kidsborn were 51.16 and 48.83 respectively. From this study it could be inferred that Tris extender with six per cent glycerol was superior to Tris extender with four per cent, five per cent or seven per cent glycerol for better post-thaw motility and fertility of frozen buck semen.